55ESPE Poster presented at: Ovotesticular Disorder of Sex Development (OT- DSD) among Egyptian DSD patients Mona Mekkawy, Alaa K Kamel, Amal M Mohamed and *Inas Mazen National research Centre. Human cytogenetics dept., *Clinical genetics dept. Patients: Among 540 DSD patients studied over a period of 5 years (2010-2015) who were referred to the Clinical Genetics and endocrinology Clinic, NRC, Cairo, Egypt, we report 8 patients with OT-DSD, The patients constituted 6% of the patients presenting with ambiguous genitalia and 1.5 % of all patients. Seven patients presented with ambiguous genitalia, One male patient presented with pubertal breast development. OT-DSD pathological diagnosis was confirmed in all patients. Methods: Detailed clinical examination Anthropometric measurements ,Hormonal assay Imaging examinations Chromosomal analysis and Fluorescence in situ hybridization (FISH) Laparoscopy, laparotomy and gonadal biopsy with gonadal histopathological examination. ,FISH on gonadal tissue cells Patient 1 2 3 4 5 6 7 8 Sex of rearing Female Female Male Female Female changed to a male Male Male Male Age (year:month) 13:00 00:09 11:08 3 years 12:00 25:10 00:06 03:06 Laparoscopy Testis like gonad (inguinal region)/ovary, Hypoplasic uterus Dysgenetic testis (inguinal region)/ovary, Left fallopian tube, uterus. A uterus and a left gonad, right scrotal swelling. Prepubertal uterus and bilateral gonads. Prepubertal uterus and no gonadal tissue visualized. Right side Fallopian tube and a small cystic ovary, uterus, left side gonad appeared as testes Normal size left testis with minimal hydrocele, Right gonad not detected. A uterus and two gonads Pathology Right: dysgenetic testis, Left: ovary with some follicular activity Right: Dysgenetic testis, left: ovotestis Both testicular and ovarian tissues within the left gonad. Rt scrotal epididymal cyst. Bilateral ovotestis. testicular Left dysgenetic testis, right ovotestis testicular biopsy: testicular tissue showing small tubules, lined by sertoli cells. left testicular tissue, right ovotestis Both testicular and ovarian tissues in the left gonad., Rt. Testicular tissues Cytogenetic results 45,X [60]/46,X, idic(Y) (p11.32)[40]. ish idic(Y)(p11.32) (wcpY+, Xp/Yp-, SRY+, DYZ3++) 45,X[75]/46,X, idic(Y) (p11.32)[15]/ 47,X,idic(Y) (p11.32)x2[4]/ 46,XY[6] ish idic(Y)(p11.32) (wcpY+, Xp/Yp-, SRY+, DYZ3++) mos 46,X,dic(X;Y)(p22.33;p11.32)[65]/45 ,X[23]/45,dic(X;Y) (p22.33;p11.32)[12]. ish: t(X;Y)(p22.33;p11.32)(DXZ1+/ DYZ3+, KAL+, SHOX–, Xp–/Yp–, SRY+). 46,XX ish: (DXZ1++/DYZ3-, SRY- ) 46,XX ish: (DXZ1++/DYZ3-, SRY-) 46,XX ish: (DXZ1++/ SRY-) 46,XY[70]/ 46,XX[30] 46,XX ish: (DXZ1++/DYZ3-, SRY-) FISH on gonadal tissue nuc ish X/Ycen(DXZ1x2,DYZ3x1)(DXZ1 con DYZ3x1) [67]/ (DXZ1x1)[23]/(DXZ1x1,DYZ3x1)(D XZ1 con DYZ3) [10] nuc ish X/Ycen (DXZ1x1)[35]/ (DXZ1x2) [55]/ (DXZ1x1,DYZ3x1) [10] nuc ish Xcen(DXZ1x2), Yp11.32 (SRY-) a) FISH analysis showing two hybridization signals for the Y centromere probe (DYZ3); (b) one signal for LSI SRY probe a) FISH analysis on blood metaphase and interphase cells of patients 4 showing two hybridization signals for X centromeres (DXZ1). b) FISH on gonadal tissue cells showing three cell lines revealing: two hybridization signals for the X centromere, one X centromeric signal and hybridization signals for both CEP X and CEP Y. a) GTG partial karyotype for the normal and derivative X chromosomes. b) FISH showing a hybridization signal for the SRY gene probe on the translocation chromosome a b Objectives Clinical, histopathological and and Cytogenetic studying of this rare form of Disorders of sex development (DSD) among Egyptian patients. Introduction Ovotesticular disorder of sex development (OT-DSD) is a rare disorder of sexual differentiation characterized by the presence of both testicular and ovarian tissues in the gonads of the same individual. The incidence of OT- DSD ranges from 3% to 10% of all DSD. Patients usually prese,nt at birth with ambiguous genitalia, and the majority show a 46,XX karyotype, with absence of the SRY sequence (Matsui et al., 2011; Khadilkar et al., 2015) The etiology may be due to 46,XX/46,XY chimerism as a result of fertilization of the ovum and the polar body or tetragametic fusion, mosaicism with various combinations (46,XX/47,XXY, 45X/46,XY) (Paula et al., 2015) or mutations of autosomal or sex chromosome genes involved in the testis-determining pathway. Results References: ● Khadilkar KS, Budyal SR, Kasaliwal R, Sathe PA, Kandalkar B, Sanghvi BV, Parelkar SV, Lila AR, Bandgar T, Shah NS. (2015) OVOTESTICULAR DISORDER OF SEX DEVELOPMENT: A SINGLE-CENTER EXPERIENCE .Endocr Pract.21:770-6. ● Matsui F, Shimada K, Matsumoto F, ItesakoT, Nara K, Ida S, Nakayama M. 2011 Long-term outcome of ovotesticular disorder of sex development: a single center experience. Int J Urol. 18:231-6. ● Paula GB, Ribeiro Andrade JG, Guaragna-Filho G, Sewaybricker LE, Miranda ML, Maciel-Guerra AT, Guerra-Júnior G. (2015) Ovotesticular disorder of sex development with unusual karyotype: patient report. J Pediatr Endocrinol Metab. 28:677- 80. Conclusions: OT DSD should be considered as one of the differential diagnoses in cases of ambiguous genitalia with non palpable or asymmetrical gonads, pubertal gynecomastia, and cyclical hematuria, irrespective of the karyotype or internal genitalia. Gonadal biopsy is important in to establish diagnosing cases of sex chromosome mosaicism. Chromosome studies carried out on peripheral lymphocytes do not always reflect the proportion of cell lines in the gonads. 416--P2 Mona Mekkawy DOI: 10.3252/pso.eu.55ESPE.2016 Gonads & DSD